Loader and forklift are self-propelled earth moving machinery which is hinged on the front of the chassis and is composed of boom, linkage and loading bucket to shovel, transport, unload and level operation during traveling. If the corresponding working device is installed, it can also push soil, lift, load and unload wood, etc. it is a widely used construction machinery.

装载机自重大，轴距短，且始终处于流动作业状态，难以用固定位置的衡器对它所载货物进行称量，否则会影响工作效率，因此，寻找一种使其在工作过程中完成对货物称重的方法，才能较好地这一问题。一般来对货物计量的准确度要求越高越好，称重误差一般要求0.1～0.5左右。 装载机进行散堆货物装载时，初期采用测比重画线估算的方法来计算所装货物的重量，此法存在着误差大、随机性大、不便管理等特点。多装，会造成直接经济损失和超载运输；少装欠载，则会降低运输效能，损害客户利益。同时，因装载机无称量装置而使物料装卸还需要依赖于汽车转运过秤或使用地磅，装卸效率低下费用也很高。随着铁路、汽车、港口、码头等物流装卸业的发展，装载上货效率和准确性的要求越来越高。需要一种的装载机称重系统来实现装载过程中对货物的自动准确计量，对于加强装载作业管理，防止超载和欠载，提高装卸作业效率和效益，保证车辆运输的性有着显著的实效。

Since the loader is heavy, the wheelbase is short, and it is always in the flow operation state, it is difficult to weigh the goods carried by it with a weighing instrument in a fixed position, otherwise it will affect the work efficiency. Therefore, to find a method to complete the weighing of goods in the working process can better solve this problem. Generally, the higher the accuracy of cargo measurement, the better. The weighing error is generally about 0.1 ~ 0.5. When the loader loads bulk goods, the weight of the loaded goods is calculated by measuring the specific gravity and drawing a line at the initial stage. This method has the characteristics of large error, randomness and inconvenient management. Over loading will cause direct economic losses and overload transportation; Less loading and less loading will reduce the transportation efficiency and damage the interests of customers. At the same time, because the loader has no weighing device, the material loading and unloading also needs to rely on the truck transfer and weighing or the use of weighbridge, which has low loading and unloading efficiency and high cost. With the development of logistics loading and unloading industry such as railway, automobile, port and wharf, the requirements of loading efficiency and accuracy are higher and higher. An advanced loader weighing system is needed to realize the automatic and accurate measurement of goods in the loading process, which has remarkable actual effect on strengthening the management of loading operation, preventing overload and underload, improving the efficiency and benefit of loading and unloading operation and ensuring the safety of vehicle transportation.

称重系统介绍

Introduction to weighing system

装载机称重系统工作原理：

Working principle of loader weighing system:

装载机称重系统一般分为两个部份，信号采集部分和信号处理及显示部分。信号采集部分一般通过传感器或者变送器实现，信号采集的准确程度对装载机的称量的准确度关重要。

The loader weighing system is generally divided into two parts, signal acquisition part and signal processing and display part. The signal acquisition part is generally realized by sensor or transmitter. The accuracy of signal acquisition is very important to the weighing accuracy of loader.

静态称重系统

Static weighing system

常用于对现有装载机或铲车的改装，由于现场没有适当的称量设备，而用户又需要进行计量以进行贸易结算时，鉴于用户对改装成本的需求，通常会选用静态计量方式。静态计量称重设备组成：压力传感器（1个或2个，视精度要求而定）+普通称重显示仪表（必要时可选配打印机）+安装附件（引压管或过程接口等）。

It is often used for refitting existing loaders or forklifts. Since there is no appropriate weighing equipment on site and users need to measure for trade settlement, in view of users' demand for refitting cost, static measurement method will usually be selected. Composition of static metering and weighing equipment: pressure sensor (1 or 2, depending on accuracy requirements) + ordinary weighing display instrument (printer can be selected if necessary) + installation accessories (impulse pipe or process interface, etc.).

静态称量的一般特点：

General characteristics of static weighing:

1）、每次称量时，称重斗的位置要求一致，以保证称量的准确性，从而影响了称重效率；

1) . during each weighing, the position of the weighing bucket shall be consistent to ensure the accuracy of weighing, thus affecting the weighing efficiency;

2）、设备功能较少，许多工作需要手工协助完成，如记录、计算等；

2) There are few equipment functions, and many tasks need manual assistance, such as recording, calculation, etc;

3）、适用于短期作业场所，不需要大量的数据处理；

3) It is applicable to short-term workplaces and does not require a lot of data processing;

4）、成本低，对一些个体经营单位或小单位比较适合；

4) Low cost, suitable for some individual business units or small units;

5）、涉及的参数少，安装调试比较方便。

5) The parameters involved are few and the installation and debugging are convenient.

动态称重系统

Dynamic weighing system

对车站、港口等大型单位的装载计量，应选择动态称重系统，以满足快速、连续计量与大量数据管理的需求。动态计量称重设备主要包括：压力传感器（2只）+动态控制仪表（带打印功能）+安装附件。

For the loading measurement of large units such as stations and ports, the dynamic weighing system shall be selected to meet the needs of rapid and continuous measurement and large amount of data management. Dynamic metering and weighing equipment mainly includes: pressure sensor (2) + dynamic control instrument (with printing function) + installation accessories.

动态计量称重设备的主要功能特点：

Main functional features of dynamic metering and weighing equipment:

1）、累计装载，重量设定、显示和超重报警功能；

1) . cumulative loading, weight setting, display and overweight alarm functions;

2）、单斗重量称重和累计、显示功能；

2) . single bucket weight weighing, accumulation and display function;

3）、货车车型选择或输入功能，货车车号录入功能；

3) . truck model selection or input function, and truck number input function;

4）、操作者、装载机编号和装车站代号输入功能；

4) , operator, loader number and loading station code input function;

5）、作业时间(年,月,日,时,分)记录功能；

5) . operation time (year, month, day, hour, minute) recording function;

6）、作业基本数据存储、打印与查询功能；

6) . job basic data storage, printing and query functions;

7）、采用动态采样和模糊算法,实现动态标定和动态称量,无须停斗,举升过程中自动称重；

7) Adopt dynamic sampling and fuzzy algorithm to realize dynamic calibration and dynamic weighing without stopping the bucket and automatic weighing during lifting;

8）、使用装载机电源供电。

8) Use the loader power supply.

9）、采用双液压传感器及高精度A/D转换器，精度更高。

9) Double hydraulic sensors and high-precision A / D converter are adopted for higher precision.

10）、可设置自动置零或手动置零。

10) . automatic zero setting or manual zero setting can be set.

适用范围

Scope of application

适用于装载机（包括铲车）自动称重计量、超载保护、工作量管理等。可称量煤或焦炭﹑有色矿﹑土方﹑花岗或大理石﹑砂子﹑碎石砖﹑工业及民用垃圾、挖掘材料及建筑添加料等。应用场所：矿山、车站、港口、码头、工厂、货场等轮式装载机。

It is suitable for automatic weighing and metering of loaders (including forklifts), overload protection, workload management, etc. it can weigh coal or coke, nonferrous ore, earthwork, granite or marble, sand, crushed stone brick, industrial and civil waste, excavation materials and building additives, etc. application places: wheel loaders in mines, stations, ports, docks, factories, freight yards, etc.

传感器的选择

Sensor selection

根据装载机的作业特点，信号采集部分一般有称重传感器、压力（油压）传感器、压力（油压）变送器三种，需要强调一点的是传感器防过载、抗震动、绝缘性、抗干扰等性能要比较好。

According to the operation characteristics of the loader, the signal acquisition part generally has three types: load cell, pressure (oil pressure) sensor and pressure (oil pressure) transmitter. It should be emphasized that the sensor has good anti overload, anti vibration, insulation and anti-interference performance.

A> 称重传感器 一般是用传感器代替销轴使用同时达到称量的目的。该方案对传感器的结构设计和安装尺寸精度要求较高，所以在实际作业中经常会出现精度低、安装更换不方便等不良现象，甚会出现事故，所以没有得到推广使用。

A> The load cell is generally used to replace the pin shaft and achieve the purpose of weighing at the same time. The scheme has high requirements for the structural design and installation dimensional accuracy of the sensor, so in the actual operation, there are often adverse phenomena such as low accuracy, inconvenient installation and replacement, and even accidents, so it has not been popularized.

B> B> 压力（油压）传感器，通过液体压力转换为装载斗的重量来完成称重作业，它改装方便快捷，设备的测量精度相对使用称重传感器大大提高，性能得到了保证。

B> B > the pressure (oil pressure) sensor completes the weighing operation by converting the liquid pressure into the weight of the loading bucket. It is convenient and fast to refit, the measurement accuracy of the equipment is greatly improved compared with the use of the weighing sensor, and the performance is guaranteed.

C> C>压力（油压）变送器，传感器输出的是mV信号，而小信号在传输和处理的时候容易受到干扰，折算出来的重量容易引起误差，对显示部分的要求比较高，在对称重精度要求比较高的系统中使用比较困难。变送器很好的了这些问题，它抗干扰能力强、输出信号大（一般为4~20mA或者0-10VDC、0-5VDC），这样对信号处理部分和显示部分要求大大降低，称重系统的准确度也相应增强。

C> C > pressure The (oil pressure) transmitter and sensor output MV signal, while the small signal is easy to be disturbed during transmission and processing, and the converted weight is easy to cause error. It has high requirements for the display part, and it is difficult to use in the system with high requirements for symmetrical weight accuracy. The transmitter solves these problems well, with strong anti-interference ability and large output signal (generally 4 ~ 20mA or 0-10vdc, 0-5vdc), which greatly reduces the requirements for the signal processing part and the display part, and enhances the accuracy of the weighing system accordingly.

D> 下面介绍两种适用于装载机或铲车称重装置的压力传感器、变送器：

D> The following describes two kinds of pressure sensors and transmitters suitable for loaders or forklift weighing devices:

溅射薄膜压力传感器

Sputtering thin film pressure sensor

本产品采用溅射薄膜技术并结合装载机称重系统的特点设计，主要通过测量装载机油压进而转换成重量信号。

This product adopts sputtering film technology and is designed in combination with the characteristics of loader weighing system. It is mainly converted into weight signal by measuring loader oil pressure.

F> 1）、该产品的主要特点：

F> 1) main features of the product:

G> a、体积小、重量轻，可直接过程安装；

G> A. small volume and light weight, which can be directly installed in the process;

b、精度高、长期稳定性好；

b. High precision and good long-term stability;

c、抗震动、冲击、过载能力好；

c. Good resistance to vibration, impact and overload;

d、耐腐蚀，耐高温，温度漂移小

d. Corrosion resistance, high temperature resistance, small temperature drift

溅射薄膜压力变送器

Sputtering film pressure transmitter

PPM-241A同样通过测量油压采集重量信号，根据客户具体要求采用数字电路对传感器信号处理。

Ppm-241a also collects weight signal by measuring oil pressure, and uses digital circuit to process sensor signal according to customer's specific requirements.

1、 该产品的特点：

1. Features of the product:

a、信号大，易换算。

a. The signal is large and easy to convert.

b、精度高，稳定性好。

b. High precision and good stability.

c、抗震动、冲击、过载能力好。

c. Good resistance to vibration, impact and overload.

d、抗干扰能力强。

d. Strong anti-interference ability.

e、耐腐蚀，耐高温，温度漂移小

e. Corrosion resistance, high temperature resistance, small temperature drift

电阻应变传感器

Resistance strain sensor

（俗称贴片式传感器PPM-242L）

(commonly known as patch sensor ppm-242l)

在装载机称量货物重量时，连接铲斗的油泵是不断运动的，油泵内的油（待测介质）经过多次高压后，温度会升高，PPM-242L传感器在应变片的选择上充分考虑了温度因素，采用高温应变片，在制作过程中采取相应措施让传感器温度漂移尽可能的小，<±0.03FS，在安装时一般是通过引压管进行安装。这样，传感器承受的温度和冲击得到缓和，从而增加了设备的使用稳定性。

When the loader weighs the goods, the oil pump connected to the bucket moves continuously, Oil in oil pump The temperature of (medium to be tested) will rise after high pressure for many times. The ppm-242l sensor fully considers the temperature factor in the selection of strain gauge, adopts high-temperature strain gauge, and takes corresponding measures to make the temperature drift of the sensor as small as possible, < ± 0.03fs. It is generally installed through the impulse pipe during installation. In this way, the temperature and impact borne by the sensor can be reduced And, thereby increasing the service stability of the equipment.

1）、PPM-242L主要特点：

1) Main features of ppm-242l:

a、精度高，长期稳定性好。

a. High precision and good long-term stability.

b、密封好，耐腐蚀。

b. Good sealing and corrosion resistance.

c、低成本，性价比高。

c. Low cost and high cost performance.

安装注意事项

Installation precautions

1）、螺纹安装应确保密封，安装时应采用密封胶或生料带等辅助用具；

1) The thread installation shall ensure sealing, and auxiliary tools such as sealant or raw material belt shall be used during installation;

2）、接线严格按照产品说明书执行，防止因误操作导致产品损坏；

2) Wiring shall be carried out in strict accordance with the product manual to prevent product damage due to misoperation;

3）、标定时应针对不同的方位、角度进行多参数测试，确保设备在各种状态下称量精度一致；

3) During calibration, multi parameter test shall be conducted for different directions and angles to ensure consistent weighing accuracy of the equipment under various states;

4）、如空间所限无法正常安装时，应考虑采用引压管引出安装的方式，调试完成后再固定好。

4) If the installation cannot be carried out normally due to limited space, it shall be considered to adopt the way of pressure pipe leading out and installation, and then fix it after commissioning.